Nothing's ever that clean and tidy. I think the whole language around "identifying as" is kind of useless... it's not effective for understanding yourself because it frames self-knowledge as an innate fact rather than something dynamic and experiential, and it's not politically effective because it doesn't unambiguously state that people are what they say they are.
Especially while you're still figuring things out, I recommend thinking about it less in term of what you are and more in terms of what you do. You can try being a girl and see how it feels! This may be easier or harder depending on your location and the people around you, but at the very least you can buy some clothes and try them on in private, and if you've got chill friends/loved ones you can ask them to try using a different name/pronouns for you and see how it fits. You can even try taking hormones for a bit—estrogen won't have any permanent effects until a few months in.
It's also worth remembering that none of this is black and white. There are plenty of people out there who are girls but only sometimes, or who are girls in some ways but absolutely not in others. You can be a girl for a few years and then be something else afterwards and that doesn't make any part of that equation any less authentic. Gender is yours to shape into something that feels good to you, but you can't know how to do that until you start playing with it a bit.

